My sample code below is exactly the same as the draggable demo, but some how it seems that the horizontal panel in mine does not get resized to the same size as LayoutContainer, which then is restricting the space of the second and third item. First item, proxy drag, looks ok in IE but not in chrome or firefox, once you drag it pass the horizontal panel and let go, scroll bars for the horizontal panel shows up, and the item is still inside the horizontal panel.

cp = new ContentPanel();
cp.setCollapsible(true);
cp.setBodyStyle("padding: 4 8px;fontSize: 12px");
cp.setHeading("Direct Drag");
cp.addText("Drags can only be started from the header.");
cp.setWidth(200);
vp.add(cp);